Articulated drive chains are frequently used in the automotive sector as timing chains in internal combustion engines and they couple the crankshaft to the at least one camshaft. Such timing drives include a guide rail in the taut span and a tensioning rail, to which pressure can be applied by means of a chain tensioner, in the slack span. When the articulated chain comes into contact with the tensioning and guide rails, friction is generated, which, in turn, leads to power losses and consequently to CO2 emission from the internal combustion engine. Reducing the friction between the rails and the chain by means of an inwardly curved shape of the link plate back is a known measure in the field of technology.
A chain of this type is known e.g. from document DE 199 07 865 A1. The chain link plates used in this chain have link plate backs comprising two spaced-apart contact portions between which an oil holding space is formed. The area of contact with the tensioning and/or guide rail is reduced in this way. Simultaneously, a lubricating-oil cushion is intended to form between the two contact portions due to the recessed shape of the link plate back.
A similar structural design is known from U.S. Pat. No. 7,963,872 B2. Also these link plates comprise two spaced-apart contact portions between which a lubricant-optimizing recessed contour is provided.
In addition, document DE 10 2010 013 572 A1 discloses an articulated chain, in which the chain link plates have convex link plate backs for providing sliding contact with the tensioning and guide rails of a chain drive, the convex link plate backs being asymmetric in shape. When the chain link plates come into contact with the tensioning or guide rail, the asymmetric shape of the link plate back allows swinging in the direction of the running direction and of the rail so as to reduce the sliding contact resistance.